1. Field of the Invention
The present invention relates to a module board embedded with an electronic component.
2. Description of the Related Art
A module board disclosed in Japanese Unexamined Patent Application Publication No. 2002-43754 is configured as follows. First, a core board having a cavity is prepared. Also, a resin film having a circuit pattern formed on a first principal surface is prepared. An electronic component is mounted on the circuit pattern of the resin film. Then, the core board and the resin film are bonded by thermocompression bonding such that the electronic component is housed in the cavity. After thermocompression bonding, the resin film is hardened by thermosetting, then a via hole penetrating through the resin film is formed, and a circuit pattern is formed on a second principal surface of the resin film. The electronic component housed in the cavity is connected to the circuit pattern on the second principal surface of the resin film through the via hole.
The resin of the resin film is fluidized and moves during thermocompression bonding, and hence the position of the circuit pattern and the position of the electronic component may vary. If the positions of the circuit pattern and the electronic component vary, a connection failure may occur with respect to the via hole formed at a predetermined position. Hence, the circuit pattern on the resin film formed for mounting the electronic component had to be large. As a result, an electronic component having multiple terminals with small pitches between terminals could not be housed in the cavity. Also, the resin could not be supplied from the resin film by an amount sufficient for filling the cavity with the resin. When the cavity is filled with the resin, the resin had to be additionally supplied.